TRD 2. QUANTITATIVE PHASE MICROSCOPY AND SPECTROSCOPY TECHNIQUES Investigators: Z. Yaqoob (2.1, 2.2, 2.3) [Lead], P. So (2.1, 2.2, 2.3); C.L. Evans (2.3) Collaborative Projects: G. Kato, U. Pittsburgh (CP2); J. Lammerding, Cornell (CP3); E. Boyden, MIT (CP4); Raman, John Hopkins (CP5); D. Fisher, MGH (CP6); P. Krauledat, PNP Research (CP7); P. Campagnola (CP8). PROJECT SUMMARY: The LBRC has been one of the leaders in interferometric imaging, including wide-field quantitative phase microscopy (QPM) and tomographic phase microscopy (TPM), with applications in label-free quantification of cellular morphology, biomechanics, and cell mass/cycle control. During the next cycle, the LBRC will push this technology forward in three fronts. First, the LBRC has successfully developed novel reflection mode QPMs based on temporal and spatial coherence. While these systems show promise to elucidate the biomechanical changes in red blood cells (RBCs), they do not have the necessary depth resolution and sensitivity to study eukaryotic cells. Given that nuclear rheology is important in diseases such as progeria and in cancer metastasis (CP3,5), we push to develop a next generation reflection-mode QPM to quantify biomechanical factors in diseases of nucleated cells (TRD2.1). Second, we have developed several generations of TPMs that provide exquisite 3D maps of the cellular refractive index (RI) distribution, but they offer low throughput and suffer from the ?missing cone? problem. Given the need to study shape variations during RBC sickling (CP2) and cancer cell migration (CP5,8), we push to explore novel tomographic reconstruction based on reflection mode QPM (TRD2.2). Third, while our interferometric imaging work has been mostly label-free, its usage is partly limited by its lack of molecular specificity. As a completely new direction, driven by the need to study (a) sickle cell disease requiring absorption contrast (CRP2), (b) melanomagenesis mechanisms requiring absorption and Raman contrast (CRP6), and (c) binding of cancer antigens to immune cells (CRP7), we push to explore the possibility of wide-field interferometric imaging with molecular specific contrast mechanisms (TRD2.3).